| 摘要 |
PCT No. PCT/SE96/00290 Sec. 371 Date Sep. 4, 1997 Sec. 102(e) Date Sep. 4, 1997 PCT Filed Mar. 5, 1996 PCT Pub. No. WO96/27711 PCT Pub. Date Sep. 12, 1996A valve mechanism for self-expanding booms. The mechanism is preferably a mechanical expansion device that folds out the boom so that air flows into the boom to fill the boom. When the boom is folded, the air is pressed out of the boom. A novel feature is an automatic control mechanism that is adapted to permit an inflow of air into the boom when the boom is expanded and to permit an outflow of air when the boom is collapsed, rolled up and stored. The control mechanism is affected by the relative position between the valve mechanism and other parts of the boom when the boom is in the expanded or collapsed position. |
